Combination paper-drier installation



9-, J. E. ALEXANDER 1,726,134 I COMBINATION PAPER DRIER mswggLm'rIbu Filed Jan. 29, 19 2'! Y Patented Aug. 27, 1929. I

UNITED STATES] JOHN E. ALEXANDER, PORT EDWARDS, WISCONSIN.

COMBINATION PAPER-DRIER INSTALLATION.

Application filed January 29, 1927. Serial {0. 16414011 This invention relates to a combination paper'drier installation and more particularly to a combination of steam heated drum driers of the common type used in paper machines with an electrically heated drier unit adapted to supply steam generated from the drying of paper thereon for utili-. zation in the drum drier.

In the drying of paper electrically as disclosed inmy Patent, No. 1,330,366, which issued February 10, 1920, the steam generated from the moisture'in the paper is available for use for heating and power purposes, due to the fact that the electric drier unit is com- 1 pletelyhoused so as to prevent the admission of substantial quantities of air. I now propose to utilize the steam so generated in the electrical drier unit in steam drier drums of standard type and also to provide a gradient heating system. By this arrangement, not

only is the economy of the electrical drier unit greatly increased, but there also results certain advantages in the drying of the paper from the fact that the paper may be dried in gradually increasing temperatures.

Other and further important advantages and objects of this invention will become apparent from the following description and the appended claims.

On the drawings: i

The figure is a diagrammatic elevational view of a combination paper machine drier installation embodying the principle of myinvention. 7

. As shown on the drawings:

' The referencenumeral 1 indicates a housing enclosing a series of hollow, steam heated drier drums 2 of standard type. The steam is adapted'to be admitted to one group A of said drier drums 2 through a header 3 and branch pipes 4 leading to the, journals of said drier'drums. In starting up the paper machine, boiler steam or steam "from other sources may be introduced into the heater 3 through a pipe 5, but after the machine has been in operation for a suflicient length of. time the steam utilized inthe group of driers A is obtained from an electrical drier unit 6 associated with the steam heated drier drums of standard type, as will later beexplai-ned.

A web of paper 7 as it is delivered from a pair of press rolls 8 on the Wet end of the machine is transferred from the press felt9 and introduced-between sealing rollslO positioned '24 to a source of vacuum (not shown).

in the end of the housing 1. Said web of paper? 1s then threaded around the lower and upper drier drums 2 in the group of driers A in the usual fashion. From the group of driers A, the web 7 passes around a certain number of drier drums forming a gl'Qup B. The web thence passps between sealing rolls 11 in the other end wall of the housing enclosing the electrical unit 6.

Within the electrical unit 6 the web 7 travels 1n superposed horizontal passes 12 between electrical heatin units (not shown). The type of electrica drier unit used is preferably that disclosed in mypatent above referred to. From the electrical unit 6'the web 7 passes out between the sealing rolls 13 and is delivered to a set of sweat driers 14 from which the web passes to a calender stock 15 and thence to the reels (not shown);

Steam generated within the housing of the electrical unit 6 is carried by means of aheader 16 leading ofi' throu h the top wall of said casing by means of ranch ipes 17 and 18 to the drum driers in grou The steam enters the driers in group through pipes 19 and is exhausted throu h pipes 20' into a lower ofiset portion 21 0% the steam header 3. The exhaust steam from the drum driers in group B then passes through header 3 and branch pipes 4 into the drum driers in group A, the exhaust and condensate from said driers passing throu h pipes 22 into a lower drain header 23. aid drain'header- 23 1s preferably connected through a pipe For the sake of better heat economy, the casing 1 is provided at the top with an exhaust conduit 25 for carryin away the heated vapors and air from insi e thecasing 1 and an economizer 26 is provided in the exhaust line 25. The economizer 26 may be of any suitable type, wherein incoming airto the casing '1 is heated by the outgoing gapors and air passing out through the conuit 25. r

In starting up the machine, as pointed out above, steam from other sources than the electrical drier unit 6 must be introduced into the steam header 3 and the'drier drums 2 in orderto secure initial drying of the paper. After the paper web has been passing throu h the drying system for a sufficient length 0 time,

however, the-steam generated inthe'electrical unit 6 from the moisture in the paper may be utilized directly in the drier drums 2, either cut referred to above.

- order to prevent sea'rin the paper and trapping the moisture therem. The temperature in the electrical drier unit 6 may, of course, be controlled within any desired limits, under the principles and means disclosed in my pat- The sweatv driers 14:

serve the usual purpose of permitting the web of paper to regain some of its normal'moisture content.

It will be apparent to those skilled in the art that a combination of drum driers and electrical drier unit as described will have other advantages besides those of an economical nature. These will manifest themselves, in part, in improved quality of paper due to better control of the temperature in the driers, and in part to the other conditions under which the paper is dried. For instance, in

ryin paper on drum driers, there is a tendency, ue to the fact that the drier felt holds the web of paper tightly against the surface of the drum, for the paper to lose some of the.

"strength that it would have were it free to contract naturally In the electrical drier unit however, the web of paper can dry more freely and retain a large measure of its natural tensile strength. On the other hand, if an electrical drierunit were used alone, the paper would not present such a good surface appearance as where the paper has passed over steam heated drier drums. The combi nation offthe electrical drier unit with thei steam heated driers therefore possesses the advantages of each type.

1 My invention alsocontemplates the installation of an electrical drier unit in conjunc- .tion with present paper machine installation having steam drum driers of the usual type.

In such a case, it would merely be necessary to lengthen the machine in order to set up the electrical drier unit between the present drum driers and the calender stack.

While for the sake'of heat economies, the

- steam drum driers should be enclosed and a 55 steam economizer used in connection with the 'exhaust from the enclosure, it will be understoodthat these points are not essentialto my mvention, Furthermore, the drum driers may be piped in various ways to receive the steam from the electrical drier unit, and they.

mtiy be in vertical tiers as well as horizontal. am aware that many changes may be made, and numerous details of construction may be varied through a wide range without departing from the principles of this invenpaper is adapted to be passed-to be dried, a

plurality of drum driers operatively associated therewith and means for conducting steam generated within the electrical drier unit from the moisture in the said drum driers.

paper web to 3. In a paper drier installation, a closed housing, an electrical drier unit therein for dryingthe paper, a plurality of drum driers arranged ahead of said electrical drier unit for eflecting'partial drying of the paper and means for conducting steam electrically generated within said housing from the moisture in said paper to said drum driers for heating the latter. i

. 4. A combined paper drier installation,

comprising a plurality of steam heated drum driers and an electrical drier unit, the web of paper being adapted to pass successively over said drum driers and through said electrical drier unit and. means connecting said electrical drier unit and said drier drum for utilizing in said drier drumssteam generated in said electrical drier unit from the moisture in said paper, said drier drums bein divided into groups for receiving all of t e steam through one of said groups first.

n a drier system, the combination with a plurality of drier drums, of an auxiliary drier unit, heatingmeans therein'for transforming a part of the water in said web into steam, and means for conducting said steam into and through said drums to heat the same.

6. In a drier system, the combination with a plurality of drier drums, of an auxiliary drier .unit, high-temperature heating means therein for transforming a part of the fluid in said web into dry"superheated vapor, and

means for conducting. said vapor'into said drums to heat the same.

7 In a drier system, the combination with a plurality of drums for operatively engaging a'web of material to dr the same, of an auxiliary drier unit for e ecting a partial drying of said web, high temperature heating means in said drier umt for transforming the water in'said web into dry superheated steam; and means for conducting the steam from the auxiliary drier unit into and through said drums to heat the same.

8. In a driersystem,.the'combination with a plurality of rotatable drums for operatively engaging a web'ofmateriall to be dried, of an auxiliary, substantially enclosed, drier cas-I ing located in the path of said webf-high temperature electric heating means in said .casing for transforming a portion of the water in said web into dry superheated steam, and means for conducting said steam into and through said drums to heat the same.

9. In a drier system, the combination with a plurality of rotatable drums for operatively engaging an initially wet web of material to be dried, of an auxiliary drier casing, means for moving said Web through said drier casing, means in said drier casing for transforming a part ofthe water in said web into dry superheated steam, and means for conducting the steam into said drums to heatthe same and to dry the web.

, 10. In adrier system, in combination, a substantially enclosed drier casing, means for moving an initially wet web of material through said casing, a plurality of rotatable drums for operatively engaging said web of material, heating means in said casing for transforming apart of the water in said web into dry superheated steam, and means for conducting said steam into and through said drums to heat the same.

In testimony whereof I have hereunto subscribed my name.

JOHN E. ALEXANDER. 

